Skin piercing devices for medical use

ABSTRACT

Apparatus for piercing skin including a skin contact surface arranged to contact a portion of skin to be pierced, a skin piercing needle arranged to pierce the skin within the region and a cooling assembly providing cooling of the skin contact surface thereby cooling the portion of skin prior to and during piercing thereof by the skin piercing needle.

FIELD OF THE INVENTION

The present invention relates to skin-piercing devices for medical use,and to cooling devices.

BACKGROUND OF THE INVENTION

The piercing of skin for purposes of administering medications andtaking blood samples is well known in medical practice. Insertion of aneedle into the skin is known to be accompanied by a localized sensationof pain. Accordingly, it would be an advantage to desensitize skin intowhich a needle is being introduced.

Various devices and methods are known in the prior art for localdesensitization of skin. Among prior art publications which describelocalized desensitization of skin are U.S. Pat. Nos. 2,746,264;2,982,112; 3,327,713; 3,826,264; 4,614,191 and 4,646,735.

In medical practice there is a known risk of accidental puncture by usedhypodermic needles. Such accidents are particularly problematic with thespread of various infectious diseases, such as AIDS and Hepatitis B,which may be transmitted by infected blood.

SUMMARY OF THE INVENTION

The present invention seeks to provide a needle assembly for medical orveterinary use, which has a needle and a retractable sleeve associatedwith the needle, so as to reduce the risks of accidental puncture by theneedle and of contamination of the exposed needle, and so as also tolimit the penetration depth of the needle.

The present invention also seeks to provide a skin piercing device whichincorporates a skin piercing element and a desensitizing element, andwhich, when placed against a portion of skin to be pierced, providesdesensitization of the skin so as to render a subsequent introductioninto the skin of the piercing element less painful.

A further aim of the present invention is to provide a skin piercingdevice which incorporates a desensitizing element together with anautomatic skin piercing element.

There is thus provided, in accordance with a preferred embodiment of theinvention, a needle assembly for medical or veterinary use, and whichincludes a needle having a needle point, and a sleeve associated withthe needle,

wherein a predetermined portion of the sleeve has elastic properties ina generally longitudinal direction and is adapted to take up a generallyextended state when the assembly is in a non-operative orientation so asto surround the entire length of the needle, and is further adapted totake up a compressed state when the assembly is in an operativeorientation, thereby to expose a portion of the needle including theneedle point.

Preferably, the portion of the sleeve having elastic properties has theform of either a helical coil or a bellows.

There is also provided, in accordance with a further preferredembodiment of the invention, apparatus for piercing skin including skinpiercing apparatus, and a cooling assembly providing a cooled surfaceassociated with the skin piercing apparatus for cooling a portion ofskin prior to and during piercing thereof by the skin piercingapparatus.

Additionally in accordance with a preferred embodiment of the invention,the cooling assembly includes a thermoelectric cooling assembly.

Alternatively, the cooling assembly may be a replaceable cooling elementadapted to be cooled independently of the apparatus for piercing skin,or fluid cooled apparatus.

Additionally in accordance with a preferred embodiment of the invention,the thermoelectrically cooled surface defines an aperture through whichthe skin piercing apparatus extends.

In accordance with one embodiment of the invention, the skin piercingapparatus includes a hypodermic syringe.

In accordance with an alternative embodiment of the invention, there isalso provided syringe flexible cover apparatus for protecting the needleof the syringe, wherein the cover apparatus is also operative to centerthe needle along a predetermined axis.

Further in accordance with a preferred embodiment of the invention,there is also provided a housing for the skin piercing apparatus and forthe thermoelectric cooling assembly, a shaft mounted in a predeterminedorientation in the housing; and means for decouplably attaching thehypodermic syringe to the shaft such that the hypodermic syringe has apredetermined orientation relative to the shaft.

There may also be provided apparatus for automatically operating thehypodermic syringe.

In accordance with an alternative embodiment of the invention, the skinpiercing apparatus includes skin pricking apparatus.

Additionally in accordance with a preferred embodiment of the invention,the skin pricking apparatus includes a needle, a needle holder,apparatus for driving the needle through the aperture, and apparatus forpreventing accidental driving of the needle through the aperture.

Further in accordance with a preferred embodiment of the invention,there is also provided apparatus for centering the needle along apredetermined axis extending through the aperture.

Additionally in accordance with a preferred embodiment of the invention,there is also provided apparatus for automatically loading the firstelastic element and for releasing the first elastic element, thereby tourge the needle holder toward and to drive the needle through theaperture.

Further in accordance with a preferred embodiment of the invention, theskin pricking apparatus is enclosed within a housing which defines apricking location adjacent to the aperture, and the apparatus alsoincludes apparatus for feeding to the pricking location and for removingtherefrom a plurality of needle modules, each including at least aneedle and a needle holder.

According to yet a further alternative embodiment of the invention, theskin piercing apparatus is a jet injection device.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be more fully understood and appreciated fromthe following detailed description, taken in conjunction with thedrawings, in which:

FIG. 1 is a perspective view of a needle assembly constructed inaccordance with an embodiment of the invention;

FIG. 2 is a side cross-sectional view of an end portion of a syringewhich has mounted thereon the needle assembly of FIG. 1;

FIG. 3 is a perspective view of a needle assembly constructed inaccordance with a further embodiment of the invention;

FIGS. 4A and 4B are side-sectional views of an end portion of a syringewhich has mounted thereon the needle assembly of FIG. 3, innon-operative and operative orientations, respectively;

FIGS. 5A and 5B are schematic side view illustrations of a manuallyoperated hypodermic injection device constructed and operative inaccordance with an additional embodiment of the invention, in respectivenonoperative and operative positions;

FIG. 5C is a schematic, partially cut-away side view of a portion of theinjection device of FIGS. 5A and 5B, constructed in accordance with analternative embodiment of the invention;

FIGS. 6A and 6B are schematic side view illustrations of an automatichypodermic injection device constructed and operative in accordance withan embodiment of the invention, in respective nonoperative and operativepositions;

FIG. 7 is a schematic side view illustration of an automatic hypodermicinjection device constructed and operative in accordance with analternative embodiment of the invention;

FIG. 8 is an enlarged side view of an end portion of a hypodermicsyringe employed in the devices of FIGS. 5A-7;

FIGS. 9A and 9B are pictorial illustrations of an end portion of thehypodermic syringe depicted in FIG. 8, prior to and during engagementwith a syringe support member constructed in accordance with a furtheralternative embodiment of the invention;

FIGS. 10A and 10B are schematic side view illustrations of a manuallyoperated pricking device constructed and operative in accordance with anembodiment of the invention, in respective nonoperative and operativepositions;

FIGS. 11A and 11B are schematic side view illustrations of the needlemodule employed in the device of FIGS. 10A and 10B, in respectivenon-operative and operative positions;

FIGS. 12A and 12B are schematic side view illustrations of a portion ofan automatic pricking device constructed and operative in accordancewith an additional embodiment of the invention, taken in the directionof arrow 12 in FIG. 13 in respective non-operative and operativepositions;

FIG. 13 is a pictorial illustration of a feed and ejector assembly ofthe pricking device of FIGS. 12A and 12B;

FIG. 14 is a pictorial illustration of a drive assembly forming part ofthe assembly illustrated in FIG. 13;

FIGS. 15A and 15B are respective side and top views of the driveassembly of FIG. 14 prior to operative engagement with a needle moduleof FIG. 13;

FIGS. 16A and 16B are respective side and top views of the driveassembly of FIG. 14 during operative engagement with a needle module ofFIG. 13;

FIGS. 17A and 17B are pictorial views of externally cooled coolingapparatus, constructed in accordance with a further embodiment of thepresent invention, in respective non-operable and operable positions;

FIG. 18 is a pictorial view of a portion of fluid cooled coolingapparatus, constructed in accordance with an additional embodiment ofthe present invention;

FIG. 19 is a schematic side view illustration of a manually operated jetinjection device constructed and operative in accordance with analternative embodiment of the invention;

FIGS. 20A, 20B and 20C are pictorial illustrations of another preferredembodiment of the present invention in three different operativeorientations;

FIG. 21 is a sectional illustration of an embodiment of the inventionincorporating the apparatus of FIGS. 20A, 20B and 20C; and

FIGS. 22A and 22B are sectional illustrations taken at lines XXIIA andXXIIB respectively in FIGS. 20A and 20B respectively.

DETAILED DESCRIPTION OF THE INVENTION

Reference is made to FIGS. 1 and 2, in which are illustrated a needleassembly, referenced generally 11, which includes a hypodermic needle 12(FIG. 2 only) having a pointed end 13 and an integral needle hub 14adapted for mounting onto an outlet end 15 of a syringe 16. Assembly 11also includes a sleeve 17 having a free end 18 which defines an opening19. Sleeve 17 further has a bellows-type flexible portion 20 and a base21 which is engaged with needle hub 14 via matching recesses 22 andprotrusions 23.

In FIG. 2 the needle assembly 11 is seen in a non-operative state,wherein sleeve 17 surrounds the entire length of needle 12, thereby tosubstantially reduce the risk of accidental puncture by needle point 13.When free end 18 of sleeve 17 is engaged so as to compress the sleeve,needle 12 is exposed via an opening 19 of the sleeve 17. In order toallow smooth compression of the sleeve 17, it may be perforated therebyto allow the escape of air which might otherwise resist suchcompression.

Reference is now made to FIGS. 3-4B, in which there is illustrated aneedle assembly 31 constructed in accordance with a further embodimentof the invention. In FIG. 4A, assembly 31 is illustrated in anon-operational orientation. In FIG. 4B, assembly 31 is illustrated inan operative orientation. Assembly 31 includes a sleeve 32 in the formof a helical coil wherein gaps 33 are provided between adjacentwindings. The sleeve 32 has a free end 34 which defines an opening 35,and also has a base 36. Assembly 31 also includes a hypodermic needle 37(FIGS. 4A and 4B) which has a pointed end 38 and a needle hub 39. Theengagement between the needle hub 39 and base 36 of sleeve 32, and themounting of the needle hub 39 onto an outlet 40 of a syringe 41 aresimilar to those of the embodiment described hereinabove in conjunctionwith FIGS. 1 and 2, and thus are not described again herein in detail.

In the non-operative orientation of needle assembly 31 illustrated inFIG. 4A, sleeve 32 surrounds the entire length of the needle and therebyprotects against accidental puncture by the needle point 38.

Referring now also to FIG. 4B, in which needle assembly 31 isillustrated in an operative orientation, it is seen that when free end34 of the sleeve 32 is pressed against skin, illustrated schematicallyat 45, sleeve 32 becomes compressed, thereby to expose the needle-point38 so as to permit penetration thereof into the skin. The distance "d"between the needle point 38 and the free end 34 of the sleeve 32 in itsfully compressed state determines the penetration depth of the needle37.

After needle 37 has penetrated the skin, a piston 42 of the syringe 41may be depressed so as to inject a liquid contained in the syringe.

In both of the needle assemblies 11 and 31 illustrated in FIGS. 1-4B,the respective needle hubs 14 and 39 are similar to hubs of prior arthypodermic needles and the assembly may be attached to and removed froma syringe outlet in a manner similar to that of prior art hypodermicneedles.

It should be noted that in the above-described embodiments, the sleeveis attached to the needle hub and is intended for one time use togethertherewith. In an alternative embodiment of the invention, the syringemay be integral with the needle assembly and the sleeve may be attachedto the syringe body directly. In this embodiment, the entireneedle-syringe assembly is intended to be discarded after a single use.

In accordance with the present invention, the penetration depth of theneedle can be adjusted by changing the length of the bellows-typeflexible portion 20 (FIGS. 1 and 2), or by changing the number ofwindings of helical coil 32 or the gap 33 between adjacent windings(FIGS. 3, 4A and 4B).

In order to enable verification of a safe injection, a lower portion ofthe sleeve may be formed of a transparent material so as to enable aperson administering an injection visual access to the needle.

It will be appreciated by persons skilled in the art that thehereinabove described needle assemblies may be modified for bloodsampling so as to be used in conjunction with skin pricking apparatus,rather than with a hypodermic syringe.

Needle assemblies constructed in accordance with the above embodimentsof the present invention provide significant advantages when used inautomatic injection or blood sampling devices. In such devices, it isnecessary to control the depth of penetration of the needle. This isknown to be provided by a relatively complex mechanism which requiresresetting prior to each operation. When using a needle assemblyconstructed in accordance with the present invention, however, thepenetration depth is predetermined by the compressed length of thesleeve and thus no adjustment of the needle assembly is required.

Furthermore, in automatic injection devices, the injection is a two stepprocess. As a first step, the needle is made to penetrate to apredetermined depth and only then is the syringe piston depressed toinject a liquid. By use of the needle assembly of the present invention,the entire injection operation may be a one step process which involvesthe application of pressure to the piston. By depressing the piston,initially, the relatively flexible sleeve will be compressed against theskin, thereby exposing the needle, which penetrates through the skin.Displacement of the piston relative to the remainder of the syringe willoccur only once the sleeve has been fully compressed, thereby ensuringthat the injection is made at the desired depth.

Reference is now made to FIGS. 5A and 5B, in which is illustrated ahypodermic injection device, referenced generally 50, constructed andoperative in accordance with an embodiment of the invention. In FIG. 5 Adevice 50 is illustrated in a non-operative position, while in FIG. 5Bdevice 50 is illustrated in an operative position.

Device 50 has a housing 51 in which are mounted a cooling assembly 52and an injector assembly 53. According to the present embodiment,cooling assembly 52 is a thermoelectric cooling assembly.

According to alternative embodiments of the invention, however, thecooling assembly may be fluid cooled apparatus or externally cooledapparatus, as shown and described hereinbelow in conjunction with FIGS.17A, 17B and 18.

According to the present embodiment, therefore, thermoelectric coolingassembly 52 typically includes a cooling plate 54, a heat transfer unit55 thermally connected to cooling plate 54, and a heat sink 57. A fan 58is preferably also provided for cooling the heat sink 57. Cooling plate54 has formed therein an aperture 59 and is mounted so to have anexterior surface 60 which is arranged to be in thermally conductivecontact with a portion of skin, as illustrated in FIG. 5B.

Injector assembly 53 includes a hypodermic syringe 61 which has a needle62, a piston 63, and a flexible cover 64 for needle 62. Cover 64 isoperative to prevent inadvertent puncture by the needle 62, thereby toperform a function similar to that of sleeve 17 (FIGS. 1 and 2) andsleeve 32 (FIGS. 3, 4A and 4B) described hereinabove. According to thepresent embodiment, however, cover 64 is made from a resilient material,such as rubber. Syringe 61 is mounted such that needle 62 is in axialregistration with aperture 59 of cooling plate 54.

It should be noted that, in an alternative embodiment of the invention,the hypodermic syringe 61 may be replaced by a jet injection device suchas shown and described hereinbelow in conjunction with FIG. 19.

According to the present embodiment, housing 51 is configured such thata portion of hypodermic syringe 61 and piston 63 protrude through thewall of the housing. Syringe 61, furthermore, is slidably mounted, via asyringe support member 65, onto a guide 66.

The use of device 50 is now described in conjunction with FIG. 5B:

Initially, cooling assembly 52 is activated, as by a suitable switchdevice (not shown) so as to cool the cooling plate 54 to a temperatureselected to desensitize the skin. Device 50 is then positioned such thatthe exterior surface 60 of cooling plate 54 contacts a portion of skin,referenced 67. After a period of time selected to desensitize the skinhas elapsed, typically in the region of no more than about five seconds,syringe 61 is then displaced manually along guide 66 in the direction ofan arrow 68 (FIG. 5B) such that an end portion 69 of the cover 64 ofneedle 62 engages cooling plate 54 so as to be compressed thereagainst.As the syringe 61 is displaced further, needle 62 emerges via aperture59 of cooling plate 54 so as to enter the skin to a predetermined depth.Piston 63 may then be depressed so as to cause injection of a liquidcontained in the syringe 61. Afterwards, the syringe 61 is withdrawnfrom the skin and the device 50 may be prepared for reuse.

Reference is now made to FIG. 5C, in which is illustrated a portion ofinjection device 50 (FIGS. 5A and 5B), constructed in accordance with analternative embodiment of the invention.

As seen in FIG. 5C, the sleeve 64 comprises a generally rigid endresilient portion 64a and a resilient intermediate portion 64bassociated with a hub 75 attached to syringe 61. End portion 64btypically contains a helical spring or the like. Cooling plate 54 has anaperture 59 which has a relatively wide, inward-facing, conical end 59awhich defines a conical engagement surface 59b. End portion 64a ofsleeve 64 has a thickened portion 64c which is configured to engageneedle 62 along a predetermined length thereof, such that the needle 62is aligned along a predetermined axis of movement 62a which iscoincident with the axis of symmetry of the sleeve. End portion 64afurther has a cone-shaped end 64d which is configured for matingengagement with conical engagement surface 59b.

Accordingly, when syringe 61 is displaced toward cooling plate 54,cone-shaped end 64d of end portion 64a of sleeve 64 engages conicalengagement surface 59b of aperture 59, thereby to lock sleeve 64 and,therefore, needle 62 along axis 62a. Further displacement of syringe 61toward cooling plate 54 causes resilient intermediate portion 64b ofsleeve 64 to be compressed, and needle 62 emerges from sleeve 64 viaaperture 59, substantially as described above in conjunction with FIGS.5A and 5B.

It should be noted that the sleeve and aperture configuration of FIG. 5Cmay be incorporated into any of the syringe devices shown and describedherewith.

Reference is now made to FIGS. 6A and 6B, in which there is illustratedan automatic hypodermic injection device, referenced generally 70,constructed and operative in accordance with an alternative embodimentof the invention. Device 70 is similar to device 50 (FIGS. 5A and 5B)described above, except that device 70 is operated automatically, asdescribed hereinbelow. Accordingly, components of device 70 thatcorrespond to components of device 50 are denoted by similar referencenumerals and are not specifically described again herein.

According to the present embodiment, there is provided an automaticinjector assembly 71 which is similar to injector assembly 53, but whichalso includes a syringe actuator and support 72, and a first motor 73.Syringe actuator and support 72 includes an axially rotatable firstdrive shaft 74 mounted so as to be generally parallel to the syringe 61.

The syringe 61 is supported on first drive shaft 74 via hub 75 and asyringe support member 65. Syringe support member 65 is internallythreaded so as to be threadably mounted onto first drive shaft 74. Aninternally threaded piston engagement member 76 is threadably mountedonto a second drive shaft 78. Second drive shaft 78 is operative todrive piston engagement member 76 therealong, via a second motor 79 andsecond gears 80, thereby to engage and depress piston 63 of syringe 61.

The use of device 70 is now described in conjunction with FIG. 6B:

Initially, cooling assembly 52 is activated, as by a suitable switchdevice (not shown) so as to cool the cooling plate 54 to a temperatureselected to desensitize the skin.

After a predetermined period of time has passed, typically no more thanabout five seconds, device 70 is positioned such that the exteriorsurface 60 of cooling plate 54 contacts a portion of skin, referenced67.

Subsequently, first motor 73 of injector assembly 71 is activated via aswitch (not shown) so as to cause an axial rotation of first drive shaft74 via first gears 77, thereby to displace syringe support member 65 andsyringe 61 therealong toward cooling plate 54.

As the syringe 61 continues to be moved towards the cooling plate 54, anend portion 69 of the cover 64 of needle 62 engages cooling plate 54 soas to be compressed thereagainst. As the syringe is displaced furtheralong first drive shaft 74, needle 62 emerges from housing 51 throughaperture 59 so as to protrude therefrom by a distance which correspondsto a predetermined injection depth.

Second motor 79 is operated to drive piston engagement member 76 towardpiston 63 via second gears 80 and second drive shaft 78, such that onceneedle 62 is at a position of maximum extension through aperture 59,piston engagement member 76 is operative to engage and depress piston63, thereby to cause injection of a liquid contained in the syringe.

Once piston 63 has been completely depressed, the directions of firstmotor 73 and second motor 79 are reversed so as to reverse thedirections of rotation of first and second drive shafts 74 and 78. Thisreverse rotation of the first and second drive shafts 74 and 78 causessyringe support member 65, syringe 61, and piston engagement member 76to be returned to their non-operative positions as seen in FIG. 6A.

Reference is now made to FIG. 7, which is an illustration of anautomatic hypodermic injection device 82 constructed and operative inaccordance with a further embodiment of the invention. Device 82 issimilar to device 70 (FIGS. 5A and 5B) described above, except thatdevice 82 employs a thermoelectric cooling assembly 83 that is differentfrom that used in device 70, as will be understood from the followingdescription. Accordingly, components of device 82 that correspond tocomponents of device 70 are denoted by similar references numerals andare not specifically described again herein.

Cooling assembly 83 includes a heat sink 84, a heat transfer unit 85 anda cooling plate 86. Heat transfer unit 85 and cooling plate 86 arearranged so as to protrude externally of housing 51 such that coolingplate 86 is used as a cold surface for directly contacting and coolingskin.

According to the present embodiment, cooling assembly 83 is arrangedacross the path of the needle 62 and has formed therein an aperture 87which extends through all the components of the cooling assembly.

Additionally in accordance with the present embodiment, aperture 87 isconfigured to have a relatively wide, conical end 88 disposed inwardlyof the housing 51 and facing needle 62. Accordingly, even if the needle62 is not properly aligned, or is slightly bent, engagement thereby of aconical surface 89 at aperture end 88 will cause the needle to becorrectly aligned.

If desired, a sterile thin layer 81 of a material formed of thermallyconductive material may be placed on the patient's skin, so as to avoidskin contact with an unsterilized cooling plate. Layer 81 may beattached to the skin with adhesive.

Reference is now made to FIG. 8, in which an end portion of syringe 61(FIGS. 5A-7) is illustrated, and to FIGS. 9A and 9B, in which areillustrated hub 75 and a syringe support member 90 adapted for usetherewith. According to the present embodiment of the invention, syringesupport member 90 is adapted for use in place of syringe support member65 (FIGS. 5A-7). Syringe support member 90 includes a base portion 91 inwhich is formed a recess 92, and a locking member 93 mounted onto baseportion 91 via a hinge 94. Locking member 93 includes a hub engagementsurface 95.

As seen in FIG. 8, hub 75 is formed so as to define an intermediateportion 96 surrounded by a pair of end portions 97. End portions 97 arepreferably spaced apart by a distance "D" that is similar to the width"W" of base portion 91, such that engagement of hub 75 with the syringesupport member 90 provides accurate positioning of the syringe 61relative to its support.

Once syringe 61 has been placed such that intermediate portion 62 of hub75 is seated in recess 92 of base portion 91, locking member 93 may beclosed such that hub engagement surface 95 engages intermediate portion96 so as to lock hub 75 and, therefore, the syringe 61, into a requiredposition. Locking member 93 may be fastened to base portion 91 via asuitable openable locking mechanism 98. In the present example, lockingmechanism 98 is a snap-type mechanism. A handle 99 may also be providedfor enabling convenient manual opening of syringe support member 90,thereby to facilitate easy replacement of the syringe 61.

Reference is now made to FIGS. 10A and 10B, in which is illustrated amanually operated pricking device, referenced generally 100, constructedand operative in accordance with an embodiment of the invention, inrespective non-operative and operative positions. Pricking device 100 istypically used for lancing or the like. Device 100 includes a housing102 in which are mounted a cooling assembly 105 and a manually operatedpricking assembly 106.

Although cooling assembly 105 may be any type of suitable coolingapparatus, it is typically a thermoelectric cooling assembly similar tothe cooling assembly 52 of device 50, shown and described hereinabove inconjunction with FIGS. 5A and 5B, and is thus not specifically describedagain herein. As seen in the drawings, cooling plate 54 which forms partof thermoelectric cooling assembly 105 has formed therein an opening 103through which a needle 104 extends during pricking operations.

If desired, a sterile thin layer 119 of a material formed of thermallyconductive material may be placed on the patient's skin, so as to avoidskin contact with an unsterilized cooling plate. Layer 119 may beattached to the skin with adhesive.

Referring now also to FIGS. 11A and 11B, according to the presentembodiment, it is seen that the manually operated pricking assembly 106includes a needle module 108 that is mounted, via a first compressionspring 110, onto a portion of the housing 102. Needle module 108includes a force transfer element 112 mounted onto the first spring 110and housed within a leader member 114 arranged within the housing 102.

Needle module 108 further includes a needle 104, a needle holder 118, aneedle housing 120 having a needle aperture 121 and a conical endportion 121a, and a second compression spring 122. Needle module 108 isarranged within housing 102 such that needle aperture 121 is inregistration with opening 103 so as to permit exposure therethrough ofthe needle 104, thereby to enable pricking. Opening 103 defines aninward-facing conical surface 103a which is adapted for engagement byconical end portion 121a of needle housing, thereby to ensure thatneedle holder 118 and, therefore, needle 104, is maintained in alignmentwith an axis of motion 104a, which coincides with the axis of symmetryof the needle housing 120.

In an at rest position, illustrated in FIGS. 10A and 11A, secondcompression spring 122 retains needle holder 118 and, therefore, needle104 in a retracted position relative to aperture 121, thereby preventingaccidental pricking. An easily pierced cap member 123 may be located atthe forward end of needle housing 120 for wiping the needle 104 as itpasses thereby preventing liquid contact between the needle 104 and theopening 103, thus preserving sterility of the needle even when thecooling plate is not sterile.

In operation, device 100 is brought into contact with a portion of skin,typically of a finger (FIG. 10B), such that the skin touches a coolsurface 124 of cooling plate 54 of the cooling assembly 105. After ashort time has elapsed to allow cooling sufficient to desensitize theskin, force transfer element 112 is manually displaced downward againstthe first compression spring 110 to the position illustrated in FIGS.10A and 11A.

Release of the force transfer element 112 enables first compressionspring 110 to urge it into engagement with needle holder 118, so as toforce needle holder 118 and needle 104 in a generally upward direction,thereby to cause needle 104 to pierce cap member 123 and to emergethrough aperture 121 and opening 103, so as to prick an adjacent portionof skin. As needle holder 118 is urged upwardly, as described, secondcompression spring 122 is compressed. Although second compression spring122 is selected to be weaker than first compression spring 110, it isnonetheless strong enough so as to assist return of the needle holder toa retracted position within the housing 102 after the required prickinghas been provided.

Reference is now made to FIGS. 12A, 12B, 13 and 14, in which areillustrated portions of an automatic pricking device, referencedgenerally 130, constructed and operative in accordance with a furtheralternative embodiment of the invention.

Referring initially to FIGS. 12A and 12B, it is seen that device 130includes a housing 132 in which are mounted a cooling assembly 134 andan automatic pricking assembly 136. Cooling assembly 134 is generallysimilar to the cooling assembly 52 of device 50, shown and describedhereinabove in conjunction with FIGS. 5A and 5B, and is thus notspecifically described again herein.

As seen in the drawings, cooling plate 54 which forms part ofthermoelectric cooling assembly 134 has formed therein an opening 138through which a needle 140 extends during pricking operations. In thepresent embodiment, the device 130 is activated via an electrical switch139 that is mounted onto the housing 132 adjacent to the cooling plate54. Switch 139 is adapted to activate device 130 when depressed by afinger 141 placed over cooling plate 54, as illustrated in FIG. 12B.

According to an alternative embodiment, however, cooling assembly 134 ofdevice 130 may be operable in response to sensing of skin contact withcooling plate 54, substantially as described hereinabove in conjunctionwith cooling assembly 105. (FIGS. 10A and 10B).

In accordance with the illustrated embodiment of the invention,automatic pricking assembly 136 includes a needle module 142 that isgenerally similar to needle module 108 described above in conjunctionwith FIGS. 12A ad 12B, except that force transfer element 112 iscontained completely within leader member 114. An upward displacement offorce transfer element 112 is provided by activation of a spring mountedhammer 144, substantially as described below in conjunction with FIGS.13-16B.

Referring now to FIG. 13, it is seen that device 130 has an assembly,referenced generally 146, for feeding needle modules 142 to a prickinglocation, referenced generally 148, and for ejecting used modules.Assembly 146 includes a needle module feed drum 150, a drive wheel 152,a motor 154 for drive wheel 152 and hammer 144.

Feed drum 150 is adapted to receive needle modules 142 from a cartridge,indicated schematically at 151, and to seat a single needle module 142in each of first and second recesses 156 and 157. Feed drum 150 isarranged for rotation about a rotation axis 158 via drive wheel 152 anda gear wheel 160 (FIGS. 14, 15B and 16B), thereby to convey a needlemodule 142 first, to pricking location 148 and subsequently, after apricking operation, to an ejection location 149.

Referring now also to FIGS. 14-16B, it is seen that hammer 144 includesa shaft 162 and a hammerhead 166 which is adapted for engaging forcetransfer element 112 (FIGS. 12A and 12B). Shaft 162 is attached to afixed support 163 via a resilient compression member 164 (FIGS. 15A and16A), such as a helical spring. Shaft 162 also has a cam follower 168which is adapted for engagement by a cam 170 formed on a bottom surfaceof drive wheel 152. Rotation of drive wheel 152 causes a correspondingrotation of cam 170 in engagement with cam follower 168. As drive wheel152 and cam 170 rotate, thereby displacing hammer 144, compressionmember 164 becomes elastically loaded. The loading reaches a maximumwhen the cam follower 168 is engaged by an edge portion 172 of cam 170.

As drive wheel 152 continues to rotate such that cam 170 moves suddenlyout of engagement with cam follower 168, the hammer is released suchthat hammerhead 166 forcibly engages force transfer element 112 (FIGS.12A and 12B) of needle module 142, thereby to operate the needle module142 substantially as described above in conjunction with needle module108 of device 100 (FIGS. 10A and 10B).

Drive wheel 152 is preferably formed with teeth 174 along apredetermined first peripheral portion 176. A second peripheral portion178 is smooth. It will be appreciated that rotation of feed drum 150occurs only when teeth 180 of gear wheel 160 are in driven engagementwith teeth 174 of drive wheel 172.

In operation of device 130, motor 154 rotates drive wheel 152 in adirection indicated by an arrow 153 so as to cause a displacement ofhammer 144 thereby to lead compression member 164. At this stage, aneedle module 142 is held at pricking location 148 via first recess 156of drum 150. At this stage, as teeth 174 of drive wheel 152 are notdrivingly engaged with teeth 180 of gear wheel 160, drum 150 remainsstationary so as to retain needle module 142 at pricking location 148.

When drive wheel 152 has rotated such that cam follower 168 is engagedby edge portion 172 of cam 170, as illustrated in FIGS. 15A and 15B, afurther slight rotation thereof is operative to release hammer 144, asillustrated in FIG. 16A. Release of the loaded hammer 144 permits areturn displacement thereof towards needle module 142. The returndisplacement of hammer 144 causes a forcible displacement thereby of theforce transfer element 112 of the needle module 142 so as to causeoperation thereof in a manner similar to that of needle module 108(FIGS. 10A and 10B).

Subsequently, drive wheel 152 continues to rotate until teeth 174thereof drivingly engage teeth 180 of gear wheel 160, thereby to causerotation of feed drum 150. As feed drum 150 rotates, the used needlemodule 142 is engaged by an ejector arm 182, thereby to cause ejectionand discarding of the used module. At the same time, second recess 157is brought into registration with cartridge 151 so as to receive a freshneedle module.

Feed drum 150 continues to rotate until second recess 157 and the freshneedle module 142 are brought into registration with the prickinglocation 148, at which time a limit switch (not shown) is activated atthis time so as to deactivate motor 154, and a positioning mechanism 184(FIG. 13) is operative to halt rotation of the drum 150 completely.

In the present example, positioning mechanism 184 comprises aspring-loaded bearing acting in conjunction with a peripheral depression186 formed in drum 150. In other embodiments, however, a positioningmechanism may be constituted by any suitable means.

Reference is now made to FIGS. 17A and 17B in which is seen coolingapparatus, referenced generally 200, suitable for use in any of thesyringe or pricking devices shown and described hereinabove. Coolingapparatus 200 comprises a removable cooling plate 202 which is adaptedfor cooling by external means, such as a refrigerator or freezer.Preferably, cooling plate 202 is made from a material having highthermal conductivity and high thermal capacity.

Cooling plate 202 defines an opening 204 and is adapted for removablemounting in a holder 206 located in a housing 208 such that opening 204is in axial registration with a needle 210. Needle 210 may be ahypodermic needle or a pricking needle as described hereinabove, or itmay alternatively be replaced by a jet injection device, substantiallyas shown and described hereinbelow in conjunction with FIG. 19.

Cooling plate 202 is typically formed with depressions 212 which areadapted to engage protrusions 214 of holder 206 so as to be supportedtherein. Cooling plate 202 may thus be made for sliding engagement withholder 206 or, if the holder 206 is made from a suitable type ofplastic, the cooling plate 202 may be made for a snap-type engagementtherewith.

Reference is now made to FIG. 18 in which is seen cooling apparatus,referenced generally 220, suitable for use in any of the syringe orpricking devices shown and described hereinabove. Cooling apparatus 220comprises a fluid cooled cooling element 222, through which a suitablerefrigerant fluid is passed via inlet and outlet conduits, referenced226 and 227, respectively.

Cooling element 222 defines an opening 224 and is positioned in ahousing 228 such that opening 224 is in axial registration with a needle229. Needle 229 may be a hypodermic needle or a pricking needle asdescribed hereinabove, or it may alternatively be replaced by a jetinjection device, substantially as shown and described hereinbelow inconjunction with FIG. 19.

Reference is now made to FIG. 19, in which is shown a jet injectiondevice, referenced generally 230. Device 230 is typically similar todevice 50 (FIG. 5A) except that injector assembly 53 thereof is replacedin the present embodiment by a jet injection assembly 232. Assembly 232is supported in a stationary position in housing 51 via suitable supportmembers 234 arid 236. Assembly 232 may be any suitable jet injectionapparatus, of which a suitable type is manufactured by Mada EquipmentCompany Inc. of 60 Commerce Road, Carlstadt, N.J. 07072, USA.

Reference is now made to FIGS. 20A-22B, which illustrate alternativeembodiments of the present invention. FIGS. 20A-20C and FIGS. 22A and22B illustrate a needle protector assembly 300 including an innerportion 302 having a recess 303 which is removably seated onto a needlemount protrusion 304 forming part of a conventional syringe. Innerportion 302 is arranged in coaxial frictional engagement with a needle305 or may be glued, or press fit thereto. Assembly 300 also includes anouter, axially slit, generally cylindrical gripping sleeve member 306,which is slidable with respect to inner portion 302.

The inner portion 302 of assembly 300 includes a rearward shoulder 307,while sleeve member 306 includes a forward shoulder portion 308 and arearward shoulder portion 309.

Seated and retained on base assembly 300, in co-axial surroundingrelationship with needle 305 is a spring 310. Seated and retained on anopposite end of spring 310 from base assembly 300 is a guide assembly312. Guide assembly 312 includes a rearward guide member 314 which isattached by a plurality of shafts 316 to a forward guide member 318.Forward guide member 318 is arranged to seat in a tapered recess portionof aperture 59 in cooling plate 54 (FIG. 21).

An easily pierced cap member 317 may be located at the forward end ofguide member 318 for wiping the needle 305 as it passes therebypreventing liquid contact between the needle 305 and the cooling plate54, thus preserving sterility of the needle even when the cooling plateis not sterile.

The operation of the apparatus of FIGS. 21-22B will now be describedwith reference to FIGS. 20A-20C. Prior to injection, the orientation 6fthe apparatus is as shown in FIG. 20A and the inner and outer members302 and 306 of the needle protector assembly 300 are in nestedorientation. During injection, as seen in FIG. 20B, the entire syringeand the needle 305 are moved forward along axis 62a, as spring 310 iscompressed, until shoulder 308 abuts the rearward end of rearward guidemember 314. In this forward motion, shoulder 308 passes a ratchet finger320 which is mounted onto cooled plate 54.

Following completion of the injection, the syringe and the needle areretracted along axis 62a, but shoulder 308 of the outer member 306 isretained against retraction by finger 320, as seen in FIG. 20C. As aresult, inner member 302 slides rearwardly out from inside outer sleevemember 306, allowing member 306 to compress radially inwardly towardsthe needle 305, as can be appreciated by comparing FIGS. 22B and 22A.

This radially inward movement causes outer sleeve 306 to be incapable ofaxially sliding over inner member 302, such that outer sleeve 306henceforth acts as a spacer between member 302 and rearward guidingmember 314, thus preventing the pointed end of the needle 305 from againextending beyond the forward guide member 318.

It is a particular feature of the present invention that the pointed endof needle 305, when in a protected orientation, is nevertheless fullyvisible and accessible.

It will be appreciated by persons skilled in the art that the presentinvention is not limited to what has been shown and describedhereinabove by way of example. The scope of the invention is limited,rather, solely by the claims which follow.

The invention claimed is:
 1. Apparatus for piercing skin comprising:askin contact surface arranged to be in thermal contact with a region ofskin to be pierced; a skin piercing needle arranged to pierce said skinwithin said region; and a cooling assembly providing cooling of saidskin contact surface thereby cooling said portion of skin prior to andduring piercing thereof by said skin piercing needle.
 2. Apparatusaccording to claim 1, and wherein said cooling assembly comprises athermoelectric cooling assembly.
 3. Apparatus according to claim 2 andalso comprising a needle cover for protecting said needle.
 4. Apparatusaccording to claim 2, and also including an automatically operatingdrive for automatically displacing said needle.
 5. Apparatus accordingto claim 4, wherein said drive comprises:a motor; and a drive train,driven by said motor, for driving a hypodermic syringe, onto which theneedle is mounted, along an axis, and for depressing a piston of saidhypodermic syringe, thereby to inject a liquid contained in saidhypodermic syringe.
 6. Apparatus according to claim 2, and wherein saidskin piercing needle comprises a skin pricking needle.
 7. Apparatusaccording to claim 2, and wherein said skin piercing needle comprises ahypodermic needle.
 8. Apparatus according to claim 1 and also comprisinga needle cover for protecting said needle.
 9. Apparatus according toclaim 8, and also comprising an drive for automatically displacing saidneedle.
 10. Apparatus according to claim 9, wherein said drivecomprises:a motor; and a drive train, driven by said motor, for drivinga hypodermic syringe, onto which the needle is mounted, along an axis,and for depressing a piston of said hypodermic syringe, thereby toinject a liquid contained in said hypodermic syringe.
 11. Apparatusaccording to claim 9, and wherein said skin piercing needle comprises askin pricking needle.
 12. Apparatus according to claim 9, and whereinsaid skin piercing needle comprises a hypodermic needle.
 13. Apparatusaccording to claim 1, and also comprising an drive for automaticallydisplacing said needle.
 14. Apparatus according to claim 13, whereinsaid drive comprises:a motor; and a drive train, driven by said motor,for driving a hypodermic syringe, onto which the needle is mounted,along an axis, and for depressing a piston of said hypodermic syringe,thereby to inject a liquid contained in said hypodermic syringe. 15.Apparatus according to claim 1, and wherein said skin piercing needlecomprises a skin pricking needle.
 16. Apparatus according to claim 1,and wherein said skin piercing needle comprises a hypodermic needle. 17.Apparatus according to claim 1, and also comprising a flexible needlecover for the needle, which cover is operative for centering said needlealong a predetermined axis.
 18. Apparatus according to claim 1, and alsocomprising:a housing for said needle and for said cooling assembly; ashaft mounted in a predetermined orientation in said housing; and meansfor decouplably attaching a hypodermic syringe to said shaft such thatsaid hypodermic syringe has a predetermined orientation relative to saidshaft.
 19. Apparatus according to claim 1 and wherein said skin contactsurface is formed with an aperture and wherein a point of said skinpiercing needle travels along an axis through said aperture. 20.Apparatus according to claim 19 and also comprising apparatus forcentering the needle along said axis.
 21. Apparatus according to claim19 and also comprising an easily pierced wiping cap member disposedalong said axis for wiping the needle prior to piercing of said skinthereby.
 22. Apparatus according to claim 1 and also comprising needleprotection apparatus for preventing unintended engagement with a pointedend of said needle.